Probiotics in Clinical Practice: An Update

Taylor Wallace & fellow researchers have written an article the was published in The Journal of Nutrition Reviews in July 2011. It is a very helpful in bringing practitioners up to date as to the evidence-based use of probiotics, particularly with respect to their potential application in clinical practice.

Probiotics in Clinical Practice

As an overview, they talk about how the human large intestine houses more than 1,000 different types of bacteria, known as microflora. Studies in recent years have shown that supplementation with health-promoting strains of bacteria can exert beneficial effects in terms of preventing certain ailments and helping to better manage others.

Metabolic Effects of Probiotics and the Gut Microflora Bacteria within the gut microflora degrade and/or ferment various substrates including starches, soluble dietary fibers, and other carbohydrate sources available in lower concentrations (oligosaccharides and portions of non-absorbable sugars and sugar alcohols). Proteins and amino acids can be effective growth substrates for colonic bacteria. The same is true for bacterial secretions, lysis products, sloughed epithelial cells, and mucins.

A wide range of bacterial enzymes degrade these materials into various intermediates, which are then fermented into organic acids, histamine, carbon dioxide, and other neutral, acidic, and basic end products.

The intermediate and end products formed in this process have been shown to provide various health influences of importance:
-Suppress Growth of Harmful Bacteria and Other Undesirable Microorganisms
-Enhanced Nutrient Absorption Carbohydrate fermentation and short-chain fatty acids improve the absorption of calcium, magnesium and phosphorus.
-Immune Modulation
-Improve Digestion
-Guard Against Antibiotic-Associated Diarrhea and Related Complications

Reduce Risk of Intestinal Infections:
-Decrease Inflammation
-Improved Intestinal Barrier

Clinical Applications and Considerations:
Research over the past 25 years suggests that probiotic supplements may be a useful adjunct in the management of various health conditions such as antibiotic-associated diarrhea, necrotizing enterocolitis, inflammatory bowel disease, and extraintestinal disorders including atopic dermatitis and recurrent urinary tract infections.

Other considerations include rheumatoid arthritis, other autoimmune diseases, immune-compromised states, psoriasis, food intolerances, and other conditions in which digestion may be compromised. Probiotic supplementation may also be a consideration as part of a colon cancer prevention program.

At present, there is no single probiotic combination considered to be the gold standard by the scientific community. Researchers in this field suggest using the probiotic bacteria that have been shown to provide the desired health outcome on a case-by-case basis.

Wallace suggests using a probiotic supplement that contains various strains of bacteria, ensuring the presence of Bifidobacteria and Lactobacilli. For example, the probiotic combination supplement shown to improve intestinal barrier function in animals with colitis included Lactobacillus casei, Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus delbrueckii (subspeciesbulgaricus), Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium infantis and Streptococcus salivarius (subspeciesthermophilus).

He also mentions that supplementation with prebiotics such as fructo-oligosaccharide (FOS) and inulin can also help spur the growth of friendly gut bacteria.

Prebiotics are the food upon which friendly bacteria thrive. Many health outcomes available from probiotic supplementation have also been shown to occur with supplementation of prebiotics. Thus, daily ingestion with soluble fiber, as well as 1,000-5,000 mg of FOS and inulin, may be helpful in the prevention and management of some of the health conditions mentioned above. As well, it seems to make sense to take a prebiotic supplement in conjunction with probiotics to optimize the potential for probiotic bacteria to thrive in the large bowel.

Common Probiotic Species:
Probiotic terminology can be a bit confusing because the word acidophilus is often used as a general name for a group of probiotic bacteria commonly used in probiotic supplements.

This common group of bacteria include:
-Lactobacillus acidophilus
-Lactobacillus casei
-Lactobacillus delbrueckii (subspeciesbulgaricus)
-Bifidobacterium species
-Streptococcus salivarius (subspeciesthermophilus)

More accurately, Lactobacillus (acidophilus, casei and bulgaris) are the common lactobacillus bacteria used in many probiotic supplements.
Bifidobacterium infantis, B. brevi and B. longum are also common Bifidobacteria that reside in the human large intestine and vagina, and are also popular constituents of probiotic formulations. Infantis was shown to dramatically reduce irritable bowel syndrome (IBS) in a recent clinical trial. The lower number of Bifidobacteria in formula-fed babies has been linked to risk of diarrhea and allergies that are usually associated with babies who are not breast-fed. As well, Bifidobacteria produce lactic acid instead of gas (like E. coli),and thus, infants and adults with more Bifidobacteria have been shown to have less gas and digestive problems.

There is also a significant difference in the incidence of antibiotic-associated diarrhea in children receiving probiotic-supplemented (enriched with Bifidobacterium) formula (16 percent) than non-supplemented formula (31 percent).

Wallace TC, et al. Human gut microbiotica and its relationship to health and disease/Nutrition Review

Dynamic Chiropractic
26 October 2011